Various automated beverage dispensers for making hot or cold beverage products are known in the art. In a conventional beverage dispenser, a metered amount of water-soluble beverage powder, stored in powder refillable canisters, and a metered amount of hot or cold water, supplied from a water source, is conveyed into a mixing chamber to produce a beverage or soup product, which is then dispensed into a receptacle and served.
The conventional dispensing units comprises a series of canisters mounted at various locations within the machine for holding large quantities of dry powder such as milk, sugar, chocolate, powdered creamer, ground tea and coffee. The canisters are generally rigid plastic or metal boxes having a removable lid to allow periodical refilling with the dry powders. On-demand dispensing of measured amounts of the powder within the canister can be produced by augering or other delivery methods that are well known in the art.
These canister-based dispensing machines have serious drawbacks. In particular, the refilling of the canisters requires time consuming manual operations from the operator. The operator has usually to refill the canisters by pouring the powder from large powder bags. This can cause significant loss of powder and hygienic problems due to possible contamination with the outside environment. Periodical cleaning of the machine is also rendered necessary to avoid these hygiene hazards.
Another problem associated with the dispensing of dry and powdered materials in canisters is that such materials are very hygroscopic and therefore have a very high tendency to form caking, bridging or rat holes within the canister. These cause serious flowing problems and consequently affect the accuracy of the metered dosage during reconstitution of the beverage. As the canisters are built to remain removable or openable, it is very difficult to ensure a tight arrangement of the canister to prevent the environmental humidity from reaching the powder, especially when the powder is left for storage during extensive periods of time, such as during several weeks or so.
Canisters due to a lack of flexibility are also cumbersome and the vending machines must be sufficiently oversized to allow the desired number of the canisters to be mounted therein. There is an increasing tendency to promote smaller vending systems but it is detrimental to the powder capacity and to the choices for varied beverages.
Therefore, there is a need for a novel dispensing device which overcomes the disadvantages of the prior art.